Block-signal system for electric railways.



M. E. LAUNBRANGH.

BLOGK SIGNAL SYSTEM FOR ELEGTRIG RAILWAYS. APPLICATION FILED DEO.14. 1 905.

Patented June 1, 1909.

2 SHEETS-SHEET 1.

M. E. LAUN'BRANGR- I 1 BLOCK SIGNAL SYSTEM FOR ELECTRIC RAILWAYS.

31110111101; FILED p50. 14. 1905.

Pa-tented'June 1, 1909,

UNITED STACES A ENT. oFFIoE.

' MALCOLM E. IIJAUNBRANCH; OF'GHICAGO, ILLINOIS, 'AssIGNoR To WESTERN ELECTRIC con- PANY OF CHICAGO, ILLINOIS; A'GORPORATION OF ILLINOIS,

- BLOCK-SIGNAL' SYSTEM FOR ELECTRIC RAILWAYSJ Application filed. December 14, 1905. Serial No. 291,671.

Specification of Letters Patent.

Patented June 1', 1909;

T all whom it may concern. I Be it known that I, MALCOLM E. LAU1-:-.

and useful Improvement in BlockeSignal Systems for Electric Railways,of whioh the following is a fullffclean concise, and exact v description, 1O

' system, and its object is toprovidean im- My invention relates to a bloc-k signal proved arrangement of apparatus and'cir-v cuits which will .be certain andreliable in operation.

My invention is 'especially'adapted' for use in connection with electric railways, and its" purpose is to give the usual danger, caution e'achend of the block will indicate a caution ignal to a car followin' the first car and and clear signals-re uired for safety.-

' In the block signa systems in common use a plurality of wires are'required' .for con-;

, necting the apparatus at veachend of the an extra rail is provide block. The greater number .of Wires the greater is ,the possibility, of said Wire's becoming crossed, grounded or open, and thereby interfering with the proper operation of the" i In my invention there. is suchan signals.

arrangement of circuits and apparatus. that but a single signaling Wireis required beinsulated wire without excessive cost, and

there is less likelihood. of trouble arising from -the signal circuit getting out of order.- Moreover, by the arrangement of the circuits of' my invention, if a wire becomes crossed or opened, danger signals will be set at one or both ends of the block. The signals themselves, in my invention, may be either the usual semaphore and lamp signals at the block stations or lamp signals in the cars. I consider the latter arrangement to be preferable, and willde'scribe such an arrange- .ment in connection with my invention,

though I donot wishto be considered as limiting myself to the use thereof. usual trolley wire-or third rail may be used to supply the source of power.

When the signals areplacefl upon the cars at t ie the car enters and leaves the lock, which rails serve as conductors to the signal apparatus on the car. By using these eXtrarails' to be engaged by brushes on the car,- 'a certain and more positive result 1s obtalned than entering the block, whether or not the block mechanism.

The

oints where given section of track, farm's'pm of the'circuit connected at oneend of. the block to- 'a' source of currentand. 'at the other to, the ground. Included-in this'circliit are relay magnets, one at'each end of the block, adapt ed' to operate signalsto indicate, upon a car is already-occupied by another car, and if so, in .izvhi'c-hdirection it .is traveling, If the block is clear, the car. uponfirst entering operates mechanism .to ,display a clean pr safety-signal. The car after entering oper' ates a switch which throughtheapparatus at entering the block. whi e the first car is therein,'and a danger signal to'the car entering atthe' other-end of the block. As the car leaves the block it operates a switch which, if no other car ision'the same block, will re- .store the apparatus to its -nori'nztl'condition.

' I- will describe myin've'ntion more particularly by reference to the accompanying w n in which; 1

Figure 1" is .a diagram of, the circuits and apparatus constituting my invention; Fig. 2' is a front elevation of step' -byeste methan ism. controlling the circuit of a soienoid employed in my invention; Fig. 3 is a side elevation Ofl'the sar'ne; and. Fig. 4 is a tr'ansverse sectional view of said stepfby-st-ep For convenience of illustration I have shown the usual trolley wire as supplying the .current for operating the sigimling mechanism. The grounded connections are under stood to be the-track rail, as is usual insuch cases. I

The equipment consists of apparatus in the usualboxes situated nearthe ends of the block; In my invention the apparatus-in these boxes iscOnnectcd-by means of a single -Wire g of low resista'nce'so that rolays at either end can be shunted out from theothor' end. At. the ends A-aud 'B of the block are insulated rails j and j, respectively. The required length of these rails, in order thata length of time, wildepend uponthe'speed at which the cars are run. For all practical .105 signal 'may be (lisplayedfona perceptible.- 1

purposes a short rail at the beginning and at the end'of the block is suiiicient. Switches C and C which operate in both. direct-ions, are mounted a short distance inward from the beginning and end, respectively, of the block. Each switch is connected to the common source of current, and is adapted to be operated by a'car entering or leaving the block, and thereby to be momentarily placed in contact with one or the other of the contact points. In tl ormal condition these switches are in the position shown in the drawing, between contact points 1 and 10 and 1 d- 10?, respectively, of the signaling at each end of the block.

al condition a circuit is closed ben he two signal boxes through wire g. This circuit may be traced as follows: from i the line L through contact 8', 'relayh, contaets 7, 4, wire g, contacts 4*, 7*, relay h, and contact 8 to ground. Inthis condition the armatures of relays 7L and h are drawn up out of contact with points 13 and 13 respectively, and rails j and j have no electrical connection with the apparatus in said boxes. Each car may be provided. with brushes M and N, adapted to engage the rails j and 7', .two' relays O and P, and three lamps G, W and R, showing, when illuminated, green, 3 White and redlights, respectively. Suppose, for example, that when a car enters the block at A there is no other carin the same block. The brushes M'and N forming the contact terminals of the signal circuit carried by the carare electrically united by the rail 7' A circuit is thus closed from the line L through the relay P, brush N, rail 9', brush M, relay 0, to ground. The relays O and P attract their armatures '0 and p, respectively,- which engage contacts 16 and 17 and close a circuit from the line'through armature p, contacts 17, 16, armature .o, to ground, said circuit ineluding lamp 1. The lighting of this white light upon a car first entering the block is the signal that. the block is clear. The-white lamp V1 will stay lighted until the car reaches that point where 'it closes the'switch C,

whereupon said light will beextinguished' .andthe green lamp G will-be illuminated. Vl/ hen the switch 0 is operated by the ear to engageeontact 1,.a circuit is closed from the line L, including a source of current, through relay d to ground. The relay (i attracts its two armatures to close contacts 2 and 3 and 5,5 to open contact 4. A. circuit is thus closed from the line L through relay e, contacts 2, 5, 3, conductor, 9 leading to apparatus at the other end B oi'thebloek, contacts 4 7 relay it, contact 8 to ground.v The magnet e is thus energized and attracts its armature e closing contact 6. -At the same time the armature e opens contact 5, thereby openin; the above described circuit through conductor g. Themagnet h is consequently der energized and allows ;i-ts armature to fall I against contact 13 and the rail j" is grounded through contacts 13 and 14. The armature 2* also steps the disk 0'. around one notch, moving the insulated part i of the disk away from contact 9. A circuit is thus closed from the line through disk i, contact 9 and relay 1 to ground. lilhen the car passes'the switch C, and'the contact, which closed but momentarily is opened again, relay (1 becomes deenergized', and likewise magnet 0, the armature e being retracted, and the disk i re maining in its advanced position. The relay Z attracts its two armaturcs and closes con- The circuit through relay It being broken at con R0 tact 7, the armature of magnet 7L drops and closes contact 13. The rail is thus connectcd to the line. through contacts 13 and 15. 'Hence that terminal of relay P which was previously grounded through rail j is now also connected, through brush N, rail '9', and contacts 13 and 15', to the line, and the relay 'P 1s therefore denergized. The armature drops back and opens the circuit of the lamp at contacts 17, thereby extinguishing said of) lamp. The denergization of relay 1 also permits its armature p to fall back and close contact 18. Since the circuit from the line through contacts 15 and 13 to rail j. is closed through relay 0 to ground, when the brush M engages said rail, said relay holds its arma ture 0 against said contact point 19. A circuit isthus closed from the line through contact 18, lamp G, contact 19 to ground. It

will thus be seen, as above stated, that at the -1 00 same time the lamp W is extinguished, the green lamp G is lighted.

If after a car has entered at A,a second car attempts to enter at B its red lamp R will be lighted. This is due to the fact that the'pri'or entering of a car at A grounded the rail y" through contacts l3-a nd 14 When the brushes of the car entering at B engage with rail 9" a circuit-is closed from the line I through relay P, brush N, rail j, and contacts 13 14 to ground, thus energizing said relay P. V The relay O obviously isnot energized, since the circuit therethrough is shunted by the low resistance path'to ground from rail y" through the closed contacts 1", 14

The circuits including lampsll and G remain open therefore at contacts. 16 and 19 respectively. The relay P attracts its armature p which engages contact 20, thereby closing. a circuit from the line through contact 20, lamp R, contact 21, to ground, lighting the red lamp R and thus indicating that there is a car already in the block coming from the opposite direction.

If after a car has entered the block at A a secondcar attempts to enter at A, its green lamp will first be lighted, thus imlirating that there is a car ahead in the same block traveling the same'dircctionQ Tli-isis due to the fact that, as above descril'icdijthc rail 1 7 is connected through contacts 13 and 15 to the line. When brushes M and N engage the rail j, relay P not energized, as is apparent, but a clrcuitls closed from the hue through relay to ground. The armature '0- is attracted by the magnet Oand engagescontact 19, and a circuit from the line is closed through contact 18, lampaG, and contact .19 to ground. The lighting of lamp Gjprior to the lighting of lamp W indicates that there is already acar in the block'going in the same direction as the second car; y

A car leavmgthe-block at B when there is no other car in the block will place the signal apparatus in its normal position'. This is accomplished -m When the car lea es the block at B it operates theswiteh C., closing contact 10*. circuit is thus closed from conductor-L to ground through relay Said relay 'attraets itsarm'ature and closes contact .11. Ac rcuit is thus closed from the line. through contact 11, relay 7t, contacts 7?, 4?, 4, 12,

andrelay 1' to ground. The relay 1". operates its armature r to step disk is, and when the disk It has moved ahead as many steps as for example, only for a few moments. I i 1 u will be seen, therefore, that upon the deenerhas thefdisk'i, contact 9 will again rest on the insulated portion-i .of disk i, thereby opening at this point the circuit through rela'y Z. The armatures of saidrelay fallback, opening contacts 12 and15. 1 Y

The step-by step mechanism shown in Figs. 2, 3 and 4 is not anessential feature of my present invention, and other mechanismfor accomplishing the same function may be substituted-therefor. As shown in the drawings, the two disks i and 7c are mounted to rotate separately on a shaft 8 and are insulated'from said shaft and from 'eachother. Each disk tend-1c has a toothed disk connectedthereto, operated by the armatures e and 1" respectively, to step said disks around. Normally the contact 9-carried by disk lcfrests onthe insulated portion i.

The operation of the mechanism by a train entering a block steps the disk i forward and closes the circuit through the contact 9; whenthe disk 7c is operated by a car lea ing the block and is moved ahead as many steps as was the disk i, the contact 9 will obviously again rest on the insulated portion i.

The contacts of switches C. and C, as before stated, are time contacts, being made, It

gizatio'n of relay Z, brought about by a car leaving the block at B, if there is no other car in the block, the signal apparatus at both ends of the block will be restored to normal position. i

\Vith the above described system, there being only a single wire 9 connecting boxes, the probable troublefrom crossesand open circuits etc. is reduced. However, if

the following -manner:'

wire 9 should become grounded, the relay It would be deenergized, since each of its terminals would then be connected to ground and contact 13 would be closed so as to connect rail 7" to ground, giving a danger signal signal apparatus, and the second to enter will have its danger signal displayed.

- VVha-t I claim is:

1. In a block signal system, the combination .with a signal circuit leading from a source of current at one end of the block "through a. single wire only to ground at the other-end of the block and-including a mag-,

net at each end of the block, of a switch contact associated with each magnet and ad apted to be operated thereby, a circuit including signaling means'and a source of current controlled by each'contact, and means operated by a car entering or leaving a block to cone trol the operation of the magnets.

2. In a block 'gnalsystem, thecombination with a normallyclosed signal circuit leading from a source of current at one end of the block through a single wire only to ground at the otherend of the block, of an electromagnet at. each end of the block, in-. Y

cluded'in .said circuit, a switch 'arnrassociated with each magnet and adapted to be operated thereby, signals adapted to be controlled by said switch arm, and means Opel ated by a car entering or leaving the block-to control the character of the signals displayed by the movement of the switch arm.

3. A block signaling system. including a single wire only extending from one end of the block tothe other, said wire being normally connected to a source of c urrcnt at one end and grounded at the other, of an. electromagnet at each end of the block having its v windings in circuit with said wire, signals controlled by said electromagnets. a switch at each end of the block, and means (nu-rated by the closing of the switch at cithcrrnd of the block to decnergize said magnets an to operate said signals.

4. In a block signaling system, thccombination with a normally. closed circuit including a source of currentand ext ending through a single signaling wire only from one-end ol' the h'lockto the other, oi magnets h, 7t, one

at each endot' the block included in said circuit, a switch at each end of the block, a

magnetd energized upon the closing of one of .said switches by a car entering the block,

said magnet in'its energization opening said circuitandthereby denergizing the magnets h, h, a local s'ignaling circuit-having acontact closed by the deenergization of said -magnet It, said signaling circuit being arranged to be thereafter closed by a car entering the block at the end at which the magnet h is located, and a local signaling circuit for the other end of the block controlled by the operationof the magnet d.

'5. In a block signaling system, the combination with a normally closed electric circuit extending through ;a single signaling wire only from one end of the block to the othdr, of a magnet at each end of the block included in said circuit, signals controlled by said magnets, a switch at oneend of the block,

means operated when the switch is closed by a car entering the block to open said circuit and control signals at both ends of the block, a switch at the other end of the block, and means operated by thesecond switch when closed by the car leaving the block to restore the signaling apparatus to its normal condition when the block is clear.

6. The combination with a track divided into blocks, and having at each end an insulated rail section, of a conductor connected to each rail section, each conductor including two switches, one normally closed'to ground and the other normally open, apparatus at each end of the block electrically connected by a single circuit extending from one end or"! the block to the other, said apparatus at each endinclu-ding magnets adapted to control said switches, a switch at each end of the block adapted to be operated by a car entering or leaving the block to control the operatron of the signal circuit, so that a car upon entering an unoccupied block the rail section at that end is connected to a source of current and the rallsection at the other end is connected to ground, carcarried brushes adapted to engage. the rail sections, and carried signals adapted to be operated by a circuit closed through the rail sections and brushes. 1

7. In a block signaling system, the combination with a normally closed electrical circuit extending through a single signaling,

ing said second switches, a normally open electric circuit for each of said magnets Z Z, a switch at each end of the block adapted to be operated by a'car entering or leaving the block,'ineans actuated when the switch is closed by a car entering the block to close brushes carried by the car and adapted to engagewith said rails, and a circuit including signals carried by the car and connected to said brushes, whereby appropriate signals are displayed when from either end.

8. A block signaling system including a single wire only extending from one end of the block to the other, said wire being normally connected to a source of current at one a car enters the block end and grounded at the other, of an electro' magnet at each end of the block having its windings in circuit with said wire, signals controlled bysaid electroinagnets, and means operated by a car entering or leaving a block at either end thereof to control the operation of said magnets.

9. In a block signal system, the combination with a circuit including a source of current and extending through a single signaling wire only from one end of a block to the other, of a magnet ateach end of the block includedin said circuit, signals in eluded 111 a circuit carried by a car, said lat-,

ter circuit being controlled by said magnets,

and means operated by a car entering or leaving a block to control the operation of said magnets. v

10. In a block signal system, the combination .with a circuit including a source of current and extending through a single signaling wire only from one end of a block to the other, of a magnet at each end of the block included in said circuit, and carcarried signals adapted to be controlled by said magnets upon a car entering the block, at either end thereof.

In witness whereof, I hereunto subscribe my name this 1st day of September A. I1, 1905.

' MALCOLM E. LAUNBRANCH. 'itnesses ROY T. ALLowAY,

E. F. BEAUBIEN. 

